Free SSL Certificate Checker
Inspect the TLS certificate presented on port 443 to confirm certificate identity, issuer, validity windows, and chain details before users hit trust errors.
Common use cases
- Confirm a certificate was installed correctly after renewal or migration.
- Review expiry dates and issuer details before planned maintenance.
- Validate that a hostname is covered by the certificate subject or SANs.
Frequently asked questions
What port does the SSL checker use?
The SSL checker connects to the public host on port 443 and inspects the presented certificate.
Can this detect an expired certificate?
Yes. The result includes certificate validity dates and related warnings when the certificate is not currently valid.